UVP Benchtop Curing System - Manual (Page 2)

ULTRAVIOLET RADIATION
The band of radiation just below the violet end of the visible spectrum is called ultraviolet. This invisible band
is divided into several regions.
BC-300 Benchtop UV Curing System
1
COSMIC RAYS GAMMA RAYS ULTRAVIOLET VISIBLE INFRA-RED RADIO WAVES
X-RAYS
--- GERMICIDAL ----- BLACKLIGHT ---
-------------- ERYTHEMAL -------------- -------------- SCHUMAN ----------------
X-RAYS 1.0 100 200 300 400 VISIBLE
Various bands exist with the lower band overlapping into the X-ray band. “Near” ultraviolet, between 320nm
and 440nm, is also known as “blacklight” or longwave ultraviolet. “Middle” ultraviolet, between 280nm and
320nm, is called “erythemal” or sun tan ultraviolet. “Far” ultraviolet, between 300nm and 400nm, is known as
“germicidal” ultraviolet.
Industrial UV curing ultraviolet extends lower to 180nm and higher to 420nm.
Ultraviolet is produced artificially by various sources: UV curing lamps, blacklight lamps, sun tan lamps,
germicidal lamps, carbon arcs, welding and cutting torches, furnaces, laboratory test and analysis equip-
ment. Nature, in the form of the sun is a major natural source.
“UV Curing” is a process involving polymerization, or crosslinking of monomers upon exposure to UV radia-
tion.
Applications comprise curing of printing inks, curing coatings for wood and paper, particleboard fillers, metal
coatings, adhesives, and prepegs.
All monomers do not polymerize when exposed to UV radiation. UV curable monomers usually include a
sensitizer, which absorbs UV energy initiating polymerization reaction in the monomer.
ADVANTAGES OF UV CURING
UV curable materials are 100% solids, with no solvents to be discharged into the atmosphere. As they
polymerize entirely, a noted reduction in air pollution results.
Plant space is saved, as the UV curing line is considerably shorter than a gas oven. Time is saved as material
reacts immediately to UV exposure negating the time lag necessary to raise coating temperature to induce
thermal curing.